Abstract: An adjustable mounting assembly for an electrical outlet box wherein a bracket is secured to a wall stud. One face of the bracket has a tongue having an axially extending threaded bore. A side wall of the outlet box has a longitudinally extending groove which receives the bracket tongue so that the box is slidably mounted on the bracket for movement forwardly and rearwardly relative to the wall stud. An adjustment bolt extends longitudinally of the groove and into a threaded bore in the tongue whereby an unlimited adjustment of the electrical box is obtainable so that the front of the box will be flush with the subsequently applied plaster or dry wall and paneling. The bolt not only functions during the adjustment of the box but also, once the desired adjusted position is obtained, it functions as a stop member to hold the box at the adjusted position.